A wide range of unusual items go on display today ahead of a major auction next month.
More than 150 lots are to be sold at Christie's South Kensington on September 5 in its Out of the Ordinary sale.
Items involved include a flying machine prop made for the 1985 Young Sherlock Holmes film, which is expected to fetch £50,000 to £80,000, a Triceratops skull and one of the world's biggest caviar dishes.
The flying machine known as the 'Waxflatter' Ornithopter from Steven Spielberg's film was made to be operational, flapping its wings through pedal power.
The Triceratops skull excavated from private land in the US is estimated to fetch £150,000 - £250,000. With its three-horned head, it is one of the most famous species of dinosaur and one of the most easily recognised.
The caviar dish, reputed to be the largest in the world, is estimated to make between £80,000 and 100,000. Likely to appeal to gourmet foodies, the privately commissioned dish is crafted in silver.
Another item in the sale is Cygan, a giant robot made in 1957 and a celebrity of the 1950s and 1960s. The eight foot giant was one of the most sophisticated robots of its time with an ability to accept spoken commands and respond to light rays. When presented at London Olympia in 1958 Cygan amazed crowds, walking around the auditorium and even showing off some dance moves. It is estimated to fetch £8,000 to £12,000.
A set of Francis Bacon's paintbrushes are also going under the hammer and are expected to fetch around £25,000.
The eight brushes which the Irish-born painter gave to fellow artist Clive Barker in 1978 are in a paint-splattered butter bean tin encased in a perspex box.
Dublin-born Bacon, who died in 1992, is one of the most sought-after modern artists.
In June, his 1966 triptych portrait of his friend, muse and lover Isabel Rawsthorne went for £11,282,500 while the first work the artist ever sold, his historic Head III, went for £10,442,500.
Head of sale Charlotte Young said: "Out of the Ordinary is a tightly curated one-off sale offering a unique opportunity to acquire something a little different from Christie's South Kensington. Each lot has been selected as either visually striking or with an intriguing story to tell, and many have never before been seen at auction.
"I cannot wait to welcome the public to the extended exhibition and to witness their reaction to the juxtaposition of such diverse lots as a Triceratops skull with a Rolls-Royce turbine fan. It is definitely a sale full of surprises that will excite the imagination."
The exhibition starts today and goes on for five weeks, offering visitors an exclusive opportunity to view pieces rarely seen on the market.